My friend always wants to come over!?

My friend always wants to come over! I just have one little problem....... her 2 year old son. She doesn't control him and make him stop touching everything. Last time she came he broke a very nice picture frame of mine and all she could respond was "oh.. he broke it" and didn't even say sorry. Then he took my hairbrush and was hitting the floor with it, and she's just said "this is what 2 year old boys do" and it BROKE! and she was just like "OMG richie" and she looked at me and said "he just broke your hairbrush" nothing more. I was just so annoyed.... how rude!! he took my babies formula which is VERY expensive and poured it on the floor... and she didn't care. Every time I go on facebook she IMs me, then asks me what I'm doing then it's "I want to come over!!" and I can't get around it... cuz she'll just keep pressuring me. Also her son makes a huge mess and she doesn't clean it! ....... she'll always text me.. I lied and said my phone is off. Sometimes she'll just show up and walk in my house.... it's so rude because I have roommates! What can I do about this?